.indicator {
  width: 50px;
  height: 25px;
  position: relative;
  background-color: skyblue;
  float: left;
  margin-left: 5px;
}

.indicator:before {
  position: absolute;
  content: '';
  border-left: 12.5px solid white;
  border-top: 12.5px solid transparent;
  border-bottom: 12.5px solid transparent;
  left: 0;
  top: 0;
}

.indicator:after {
  position: absolute;
  content: '';
  border-left: 12.5px solid skyblue;
  border-top: 12.5px solid transparent;
  border-bottom: 12.5px solid transparent;
  right: -12.5px;
  top: 0;
}

.index1 {
  z-index: 1;
}

.index2 {
  z-index: 2;
}
